Data transmission method

Abstract

This invention proposes efficient data transmission methods in the mobile cellular network. A specific resource pool is divided into several resource groups to indicate the size level of the data available for transmission. The base station allocates a proper UL grant to the terminal. Based on the allocated UL grant, the terminal compares the granted Transport Block (TB) size with the size of data available for transmission. If the UL grant is large enough, the terminal transmits the data available for transmission in the allocated UL resource, otherwise, re-attempts the random access procedure. In another example, the terminal transmits a BSR message and as much of the data as is available for transmission. The base station may grant additional UL resources if there is remaining data to be transmitted. A timer is used for the terminal to decide whether waiting for the additional UL grant from the base station.

What is claimed is: 
     
       1. A data transmission method, comprising:
 receiving broadcast information from a base station by a terminal, wherein the broadcast information comprises at least one specific resource pool and at least one non-specific resource pool for a random access preamble; 
 utilizing the at least one specific resource pool to perform a random access procedure of data transmission by the terminal when the terminal meets at least one condition; 
 receiving random access response from the base station, wherein the random access response comprises allocated uplink (UL) resource; and 
 transmitting a media access control (MAC) package data unit (PDU) in message 3 (MSG 3) in the allocated UL resource, wherein the MAC PDU comprises data available for transmission from an application layer to the base station. 
 
     
     
       2. The data transmission method of  claim 1 , wherein the at least one specific resource pool and the at least one non-specific resource pool are classified by at least one of the classification: different sets of preamble sequences, or by different sets of composite time-frequency regions, or by different sets of preamble sequences and composite time-frequency regions. 
     
     
       3. The data transmission method of  claim 1 , wherein the at least one specific resource pool is utilized for the random access procedure of non-radio resource control (RRC) connection to transmit traffic data, and the at least one non-specific resource pool is utilized for the terminal to perform the random access procedure for RRC connection (re-)establishment procedure. 
     
     
       4. The data transmission method of  claim 1 , wherein the at least one condition is at least one of the following conditions:
 a traffic data package from the application layer is bigger than zero; 
 a size of the data available for transmission in the terminal is small than a threshold; 
 a channel condition is better than a threshold; 
 a delay requirement is less than a threshold; and 
 an expected data-arrival interval is large than a threshold. 
 
     
     
       5. The data transmission method of  claim 4 , wherein the data available for transmission comprises at least one of the followings: terminal identification information, routing information in a core network- and the traffic data package from the application layer. 
     
     
       6. The data transmission method of  claim 1 , further comprising determining whether the at least one condition is met by the terminal, and selecting the at least one specific resource pool for the data transmission of a non-RRC connection if the at least one condition is met. 
     
     
       7. The data transmission method of  claim 6 , further comprising determining whether the at least one condition is met by the terminal, and establishing a traffic data transmission of a RRC connection if the at least one condition is not met. 
     
     
       8. A data transmission method, comprising:
 receiving broadcast information from a base station by a terminal, wherein the broadcast information comprises at least one specific resource pool and at least one non-specific resource pool, and the at least one specific resource pool comprises at least one resource group; 
 transmitting a preamble sequence by a terminal to the base station over a time-frequency region, wherein at least one of the preamble sequence and the time-frequency region is selected from the at least one resource group in the specific resource pool; 
 receiving random access response from the base station, wherein the random access response comprises allocated uplink (UL) resource; and 
 transmitting a media access control (MAC) package data unit (PDU) in message 3 (MSG 3) in the allocated UL resource, wherein the MAC PDU comprises data available for transmission from an application layer to the base station. 
 
     
     
       9. The data transmission method of  claim 8 , wherein determining by the terminal whether a condition for utilizing the specific resource pool is met before transmitting the preamble sequence by the terminal to the base station over the time-frequency region. 
     
     
       10. The data transmission method of  claim 9 , wherein the condition is at least one of the following conditions:
 a traffic data package from the application layer is bigger than zero; 
 a size of the data available for transmission in the terminal is small than a threshold; 
 a channel condition is better than a threshold; 
 a delay requirement is less than a threshold; and 
 an expected data-arrival interval is large than a threshold. 
 
     
     
       11. The data transmission method of  claim 8 , wherein before transmitting the preamble sequence by the terminal to the base station over the time-frequency region further comprising:
 calculating a size of the data available for transmission by the terminal; 
 matching the calculated size to a size level; and 
 selecting the resource group from the specific resource pool according to a pre-defined mapping rule, wherein the resource group is corresponding to the size level. 
 
     
     
       12. The data transmission method of  claim 11 , wherein that the data available for transmission comprises at least one of the followings: terminal identification information, routing information in a core network- and the traffic data package from the application layer. 
     
     
       13. The data transmission method of  claim 8 , wherein before transmitting the preamble sequence by the terminal to the base station over the time-frequency region further comprising:
 calculating a channel condition by the terminal; 
 comparing the channel condition to a threshold; and 
 selecting the resource group from the specific resource pool according to the channel condition and a pre-defined mapping rule. 
 
     
     
       14. The data transmission method of  claim 8 , wherein that the at least one specific resource pool is utilized for the data transmission of a non-RRC connection. 
     
     
       15. The data transmission method of  claim 8 , further comprising:
 after transmitting the preamble sequence over the time-frequency region to the base station, 
 receiving and decoding a random access response by the terminal to acquire a uplink (UL) grant in the random access response; and 
 determining whether a size of a granted transmission block (TB) is equal to or larger than a size of the available data for transmission by the terminal. 
 
     
     
       16. The data transmission method of  claim 15 , wherein the UL grant in the random access response grants the base station to receive the preamble sequence through the time-frequency region, and determines the size of the data available for transmission for the UL grant according to the time-frequency region and the data level corresponding to the resource group where the preamble sequence belongs to. 
     
     
       17. The data transmission method of  claim 15 , wherein determining whether the size of the granted transmission block (TB) is equal to or larger than the size of the available data for transmission by the terminal further comprising:
 when the size of the granted TB is equal to or larger than the size of available data to transmit, the terminal transmits all the data available for transmission in the allocated UL resource. 
 
     
     
       18. The data transmission method of  claim 15 , wherein determining whether the size of the granted transmission block (TB) is equal to or larger than the size of the available data for transmission by the terminal further comprising:
 when the size of the granted TB is equal to larger than the size of data available for transmission, multiplexing MAC Service Data Units (SDUs) which contain all the data available for transmission in the MAC PDU, storing the MAC PDU in a Msg 3 buffer, and transmitting the Msg 3 in the allocated UL resource by the terminal. 
 
     
     
       19. The data transmission method of  claim 15 , wherein determining whether the size of the granted transmission block (TB) is equal to or larger than the size of the available data for transmission by the terminal further comprising re-attempting the random access procedure by the terminal when the size of the granted TB is smaller than the size of data available for transmission. 
     
     
       20. The data transmission method of  claim 15 , wherein determining whether the size of the granted transmission block (TB) is equal to or larger than the size of the available data for transmission by the terminal further comprising when the size of the granted TB is smaller than the size of data available for transmission, triggering a Buffer Status Report (BSR) with a decreasing priority order until the UL grant is exhausted, storing the MAC PDU in the Msg 3 by the terminal and transmitting the Msg 3 in the allocated UL resource to the base station. 
     
     
       21. The data transmission method of  claim 20 , wherein the available data for transmission comprises terminal identification information, routing information in the core network, a BSR MAC Control Element and the traffic data package from the application layer. 
     
     
       22. The data transmission method of  claim 20 , further comprising:
 storing the MAC PDU in the Msg 3 by the terminal; 
 receiving and decoding a contention resolution by the terminal, after transmitting the Msg 3 in the allocated UL resource to the base station; and 
 receiving an additional UL grant from the base station by the terminal; 
 transmitting remaining data on the additional UL resource indicated by the additional UL grant by the terminal, wherein the remaining data is subtracting the transmitted data when the UL grant is exhausted from the size level of the data of the granted transmission region. 
 
     
     
       23. The data transmission method of  claim 22 , wherein after transmitting the remaining data on the additional UL resource indicated by the additional UL grant further comprising: receiving an acknowledgement (Ack) message for confirming the remaining data from the base station by the terminal. 
     
     
       24. The data transmission method of  claim 20 , further comprising:
 transmitting the Msg 3 on the allocated UL resource to the base station by the terminal; and 
 initiating an additional UL grant timer by the terminal. 
 
     
     
       25. The data transmission method of  claim 24 , further comprising re-attempting the random access procedure by the terminal if the additional UL grant timer is expired.